Reactive combustion engine



Nov. 22, 1932.

K M. URQUHART REACTIVE COMBUSTION ENGINE Filed Sept. 5. 19:50

2 Sheets-Sheet '1 Nov. 22, v1932. K. M. uR uHAR'r REACTIVE COMBUSTION ENGINE Filed Sept. 5, 1950 2 Sheets-Sheet 2 dam/ 1 Patented Nov. 22, 1932 UNITED STATES KENNETH M. URQUHART, F NORFOLK, VIBGINLA BEACTIVE COMBUSTION ENGINE Application filed September 5, 1930. Serial No. 480,010.

My invention relates to reactionary combustion engines and more particularly to this type of engine as applied to the propulsion of airplanes.

Heretofore it has been proposed to apply the rocket or reactive forces of a jet of fast moving gas to transportation but such devices contemplate the use of gun powder, which is dangerous to handle and also necessitates the use of numerous costly and heavy combustion chambers and ignition apparatus.

The burning of a mixture of liquid hydrogen and oxygen in a combustion chamber and the ejection of the products of combustion through a nozzle with reactive propelling effecthas also been proposed-by prior workers in the art, particularly where travel at high altitude was contemplated. However for propulsion in altitudes approxi-- mating the atmospheric air strata surround ing the earth it is not necessary to use liquid oxygen and hydrogen, which is quite expensive.

It is the object of my invention to provide an engine of the reactive combustion type capable of utilizing a common fuel such as (for example) petroleum and air.

Another object of my invention is to pro- 39 vide an internal combustion engine so constructed that the velocity of air or the velocity of the vehicle through air provides the iole compression means for compressing the uel.

Another object of my invention is to provide-an internal combustion engine capable of utilizing the velocity of air or the velocity of the vehicle through air for positively feeding the fuel from the fuel tank to the 0 combustion chamber.

A further object of my invention is to provide an internal combustion engine with means for utilizing the velocity of air or the velocity of the vehicle through air for supplying compressed air to the passengers in the cabin of the vehicle.

A still further object of my invention is to provide a device especially suitable for extreimcly high speed travel at very great altitu es.

Still further objects will become apparent by reference to the accompanying drawings, where:

Figure 1 is a side view partly in cross section; Fig. 2 is a sectional view taken on the line 2-2; and

Fig. 3 is an end view taken on the line Referring now to the drawings in detail wherein I have illustrated one embodiment of my invention 25 is an airplane comprising a housing or cabin 26 of sheet metal or other suitable construction. A conventional motor 27, having the usual propeller shaft 28 and propeller 29 is mounted within the cabin 26 adjacent the forward end thereof. This motor is employed in starting for effecting the necessary compression of air, as will be presently explained.

Also mounted in the cabin 26, access to which may be had by means of a door 34, is my improved reactionary type of combustion engine 30, a bracket 16 and bolts 17 being employed to secure the engine in place. The en- 5 gine 30 comprises a metal shell 31 formed of front and rear sections 1 and 2 screwed together as at 32, the forward section 1 being formed with an air inlet nozzle 5, which extends through the front wall of the cabin 26 and heads into the wind or direction of travel of the vehicle. The shell 31 is gradually enlarged in a rearward direction like the back half of a Venturi tube, up to a point midway its ends, and from that point rearwardly is of uniform dimension. This gradually enlarging portion of the shell serves to convert the velocity energy of the air rushing in through nozzle 5 into pressure energy, and to build up a pressure greater than atmospheric pressure in this part of the shell, while the fully enlarged rear portion forms a combustion chamber 33, which is preferably lined with an outer refractory lining 3 and inner insulating lining 4. The rear end of the shell 31' is provided with a flared discharge nozzle 5' so shaped as to permit efficient expansion of the escaping products of combustion.

Fuelis fed to the combustion chamber 33 100 from fuel tank 8 through fuel delivery pipe fitted into the discharge end of the injection tube 6 imparts a swirling tangential motion to the fuel and air as they are injected into the chamber 33. As the tank 8 and the receiving end of the pipe 10 are higher than the discharge end of the latter, the fuel Wlll flow under-the action of gravity when the control valve 9 in pipe 10 is open. However, it being essential that the fuel be compressed and positively fed, the fuel tank 8 is provided with a compression or forcing tube or pipe 11 which extends at its open forward end through the front of the cabin in position to receive the blast of air created by the propeller 29 or by the travel of the ship through the air. At its rear end this pipe 11 communlcates with the to of the fuel tank and at this point is provi ed with a regulating valve 12. 'In starting the reactionary engine 30, the airplane or other vehicle in which the engine 30 is employed must be propelled by the conventional motor 27, up to a speed high enough toinsure a fair degree of air compression in combustion chamber 33, or the blast of air entering air inlet nozzle 5 and air injection and fuel tube 6 must be aided by the action of the propeller. Under some conditions, a special high speed propeller might be used alone for providing an air blast of sulficient velocity with which to start the reactionary motor 30. When the desired pressure has been built up in the combustion chamber 33, firing of the combustible charge therein is effected by means of spark plug 13, screwed into the .forward section 1 of the steel shell 31 at a I point where it will be somewhat shielded from the high temperature existing inside the combustion chamber when the engine is under full operation. Current flows from battery 15 through'line 37 to switch 14 grounded in the frame of the vehicle, and thence back to and through the spark plug 13 to the battery 15.

The operation is as follows:

Because of forward movement of the plane or because of forward movement of plane and blast from the propeller or the blast of the propeller alone, a blast of air is directed into the nozzle 5 and on into the shell 31. As the air passes on into the Venturishaped end of the inlet nozzle 5 its velocity decreases and its velocity energy is converted into pressure energy, resulting in a pressure which extends through the portion of the shell of large diameter. From the high pressure region of the shell the air passes into the exhaust nozzle 5 where the pressure energy is reconverted into velocity energy and the air exits a-t-high velocity. Now air is also being directed into the fuel injection tube 6 and forcing tube 11. The blast of air sets up a pressure in the forcing tube 11 and by suitable opening the regulating valve 12 pressure may be built up in the fuel tank. By opening the fuel valve 9 fuel is passed from the tank through tube 10 into the injection tube 6. At the point where fuel is admitted into tube 6 the velocity energy of the rushing'ai r has not been converted into pressure energy. Beyond this point the diameter of the tube 6 increases, and a pressure builds up equal to that in the shell 31. The tube 6 finally discharges its fuel laden air through the cone shaped disperser 7 and the fuel and air are discharged into the combustion chamber 33 with a swirling motion which distributes the fuel evenly. If now the switch 14 is turned on and plug 13 starts sparking, ignition of the fuel results, and the products of combustion are heated up or caused to absorb heat energy.

. At the inlet nozzle 5 the air posseses velocity energy which is converted in the venturi shaped part of the shell 31 into pressure energy by gradually slowing up the velocity. At the point where the pressure exists, fuel is burned and heat energy is added to the pressure energy of the gases. The pressure and heat energy together are used in the expanslon nozzle 5 or converted in this nozzle 5 to eject the products of combustion at a much higher velocity than that at which the air entered the shell. Of course, in order that the products of combustion will be discharged away'from the device faster than the air entered, the products of combustion must have something to kick back on, by means of which to lift themselves to a higher velocity. The nozzle 5 provides a surface for this purpose, that is, a surface against which the products of combustion may act in pushing the plane forward. The faster the device is traveling forward the more efficient the products of combustion streaming from nozzle 5' are in propelling it forwar The separate fuel injection tube 6 is provided so that the fuel may be ignited or burned in the air, only after the air has been in the injection tube is such that the mixture is too rich to support combustion and consequently the flame does not strike back into the fuel injection tube.

After the device is in full operation the propeller used in starting off may be shut down as it is only in the way of extreme speeds. It should also be noted that after ignition starts the refractory 4 soon becomes heated to high temperature and the switch 14 may then be shut off. To stop the device the fuel valve 9 is closed.

In high altitude travel it is essential that the pressure in the cabin 26 approximate atmospheric conditions in order that passengers may breathe comfortably. Consequently it becomes necessary air or oxygen into the cabin 2'6 and that the by t to introduce compressed the products of combustion therefrom, wheree reaction of the exhausting products of latter be of such construction that it will combustion propels the air lane.

withstand considerable internal pressure.

For the purpose of utilizing the velocity of the air or the velocity of the vehicle through the air for supplying compressed air to the passengers in the cabin 26 of the vehicle a com ression tube 1 secured to the outer part of t e shell 30, is adopted like the tubes 5 and 6, previously described to be exposed to the air blast. This tube 1' is provided with the regulating cock 2, and the part of the tube which extends rearwardly past the cock 2' is enlarged thus forming a chamber in which the velocity of the air is reduced and in which the velocity energy is transformed into pressure energy. Adequate air pressure is thus built up in the cabin, the amount of pressure of course being dependent upon velocity of the air blast. Some air leakage out of the rear and sides of the cabin is to be expected, but the compression tube 1 supplies suflicient air to make up for this loss. To maintain an even pressure the cock 2 must be so adjusted as to ust supply the leak-" age loss.

What I claim as my invention is: I

1. In a combustion engine for propelling vehicles, a combustion'chamber, a fuel tank, means for providing a charge of air at high velocity to said fuel tank for-compressing the fuel therein, means for passing a combustible charge into said chamber, means for firing the charge, means for providing a charge of air at high velocity for compressing the combustible charge in said combustion chamber, the velocity of said charge of air varying with the speed of travel of the vehicle, said chamber having anexhaust opening for passing the products of combustion therefrom, whereby the reaction of the exhausting products of combustion propels the vehicle.

2. In a combustion engine for propelling airplanes a fuel tank and a combustion chamber, separate means effective according to the speed of travel of the airplanes for introducing separate charges of compressed air to said fuel tank and to said combustion chamber, said combustion chamber having an exhaust opening for passing the products of combustion therefrom, whereby the reaction of the exhausting products of combustion propels the vehicle.

3. In a combustion engine for propelling airplanes, a fuel tank, a combustion chamber, means for discharge of fuel fromsaid tank to the combustion chamber, a forcing tube extending from said tube to the front of the vehicle and affected by the speed of travel of the airplane for conducting a charge of air to the fuel tank, said combustion chamber having an exhaust opening for passing In testimony whereof I a x my signature.

KENNETH M. URQUHART. 

